Description

IPR013197 is a RNA polymerase III subunit RPC82-related, helix-turn-helix.

<p>DNA-directed RNA polymerases [ec:2.7.7.6] (also known as DNA-dependent RNA polymerases) are responsible for the polymerisation of ribonucleotides into a sequence complementary to the template DNA. In eukaryotes, there are three different forms of DNA-directed RNA polymerases transcribing different sets of genes. Most RNA polymerases are multimeric enzymes and are composed of a variable number of subunits. The core RNA polymerase complex consists of five subunits (two alpha, one beta, one beta-prime and one omega) and is sufficient for transcription elongation and termination but is unable to initiate transcription. Transcription initiation from promoter elements requires a sixth, dissociable subunit called a sigma factor, which reversibly associates with the core RNA polymerase complex to form a holoenzyme [[cite:PUB00000061]]. The core RNA polymerase complex forms a "crab claw"-like structure with an internal channel running along the full length [[cite:PUB00033173]]. The key functional sites of the enzyme, as defined by mutational and cross-linking analysis, are located on the inner wall of this channel.</p> <p>RNA synthesis follows after the attachment of RNA polymerase to a specific site, the promoter, on the template DNA strand. The RNA synthesis process continues until a termination sequence is reached. The RNA product, which is synthesised in the 5' to 3' direction, is known as the primary transcript.</p> <p>Eukaryotic nuclei contain three distinct types of RNA polymerases that differ in the RNA they synthesise:</p> <ul> <li>RNA polymerase I: located in the nucleoli, synthesises precursors of most ribosomal RNAs.</li> <li>RNA polymerase II: occurs in the nucleoplasm, synthesises mRNA precursors.</li> <li>RNA polymerase III: also occurs in the nucleoplasm, synthesises the precursors of 5S ribosomal RNA, the tRNAs, and a variety of other small nuclear and cytosolic RNAs.</li> </ul> <p>Eukaryotic cells are also known to contain separate mitochondrial and chloroplast RNA polymerases. Eukaryotic RNA polymerases, whose molecular masses vary in size from 500 to 700kDa, contain two non-identical large (>100kDa) subunits and an array of up to 12 different small (less than 50kDa) subunits.</p> <p>This family consists of several DNA-directed RNA polymerase III polypeptides which are related to the Saccharomyces cerevisiae (Baker's yeast) RPC82 protein. RNA polymerase C (III) promotes the transcription of tRNA and 5S RNA genes. In S. cerevisiae, the enzyme is composed of 15 subunits, ranging from 10kDa to about 160kDa [[cite:PUB00011444]]. This region is probably a DNA-binding helix-turn-helix.</p>

This description is obtained from EB-eye REST.

Associated GO terms

Unable to find any GO terms for the transcript with the identifier.

Associated Lotus transcripts 4

Co-occuring domains 1

A list of co-occurring predicted domains within the L. japonicus gene space: